docs: update docstrings and metadata

[yoshi-automation]

This PR was generated using Autosynth. 🌈

Commits in this repo since last synth:
5defe2b chore: release 1.5.3 (#289)
6ffc44c build: update windows configuration to match new vm

Log from Synthtool

synthtool > Executing /tmpfs/src/git/autosynth/working_repo/synth.py.
synthtool > Ensuring dependencies.
synthtool > Pulling artman image.
latest: Pulling from googleapis/artman
Digest: sha256:5599b61e56a372d21b671969ee915fbca0f6c3a0daaeb898d01f8f685f1bbc8b
Status: Image is up to date for googleapis/artman:latest
synthtool > Cloning googleapis.
synthtool > Running generator for google/cloud/bigquery/datatransfer/artman_bigquerydatatransfer.yaml.
synthtool > Generated code into /home/kbuilder/.cache/synthtool/googleapis/artman-genfiles/js/bigquerydatatransfer-v1.
.eslintignore
.eslintrc.yml
.github/ISSUE_TEMPLATE/bug_report.md
.github/ISSUE_TEMPLATE/feature_request.md
.github/ISSUE_TEMPLATE/support_request.md
.github/PULL_REQUEST_TEMPLATE.md
.github/release-please.yml
.jsdoc.js
.kokoro/common.cfg
.kokoro/continuous/node10/common.cfg
.kokoro/continuous/node10/docs.cfg
.kokoro/continuous/node10/lint.cfg
.kokoro/continuous/node10/samples-test.cfg
.kokoro/continuous/node10/system-test.cfg
.kokoro/continuous/node10/test.cfg
.kokoro/continuous/node12/common.cfg
.kokoro/continuous/node12/test.cfg
.kokoro/continuous/node8/common.cfg
.kokoro/continuous/node8/test.cfg
.kokoro/docs.sh
.kokoro/lint.sh
.kokoro/presubmit/node10/common.cfg
.kokoro/presubmit/node10/docs.cfg
.kokoro/presubmit/node10/lint.cfg
.kokoro/presubmit/node10/samples-test.cfg
.kokoro/presubmit/node10/system-test.cfg
.kokoro/presubmit/node10/test.cfg
.kokoro/presubmit/node12/common.cfg
.kokoro/presubmit/node12/test.cfg
.kokoro/presubmit/node8/common.cfg
.kokoro/presubmit/node8/test.cfg
.kokoro/presubmit/windows/common.cfg
.kokoro/presubmit/windows/test.cfg
.kokoro/publish.sh
.kokoro/release/docs.cfg
.kokoro/release/docs.sh
.kokoro/release/publish.cfg
.kokoro/samples-test.sh
.kokoro/system-test.sh
.kokoro/test.bat
.kokoro/test.sh
.kokoro/trampoline.sh
.nycrc
.prettierignore
.prettierrc
CODE_OF_CONDUCT.md
CONTRIBUTING.md
LICENSE
README.md
codecov.yaml
renovate.json
samples/README.md
npm WARN npm npm does not support Node.js v12.14.1
npm WARN npm You should probably upgrade to a newer version of node as we
npm WARN npm can't make any promises that npm will work with this version.
npm WARN npm Supported releases of Node.js are the latest release of 6, 8, 9, 10, 11.
npm WARN npm You can find the latest version at https://nodejs.org/
npm WARN deprecated core-js@2.6.11: core-js@<3 is no longer maintained and not recommended for usage due to the number of issues. Please, upgrade your dependencies to the actual version of core-js@3.

> core-js@2.6.11 postinstall /tmpfs/src/git/autosynth/working_repo/node_modules/core-js
> node -e "try{require('./postinstall')}catch(e){}"


> protobufjs@6.8.8 postinstall /tmpfs/src/git/autosynth/working_repo/node_modules/protobufjs
> node scripts/postinstall

npm notice created a lockfile as package-lock.json. You should commit this file.
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@2.1.2 (node_modules/fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@2.1.2: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})

added 581 packages from 902 contributors and audited 1428 packages in 13.913s
found 0 vulnerabilities

npm WARN npm npm does not support Node.js v12.14.1
npm WARN npm You should probably upgrade to a newer version of node as we
npm WARN npm can't make any promises that npm will work with this version.
npm WARN npm Supported releases of Node.js are the latest release of 6, 8, 9, 10, 11.
npm WARN npm You can find the latest version at https://nodejs.org/

> @google-cloud/bigquery-data-transfer@1.5.3 fix /tmpfs/src/git/autosynth/working_repo
> eslint --fix '**/*.js'


/tmpfs/src/git/autosynth/working_repo/samples/quickstart.js
  18:38  error  "@google-cloud/bigquery-data-transfer" is not found  node/no-missing-require

/tmpfs/src/git/autosynth/working_repo/samples/test/quickstart.test.js
  17:26  error  "chai" is not found  node/no-missing-require

✖ 2 problems (2 errors, 0 warnings)

npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! @google-cloud/bigquery-data-transfer@1.5.3 fix: `eslint --fix '**/*.js'`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the @google-cloud/bigquery-data-transfer@1.5.3 fix script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/kbuilder/.npm/_logs/2020-01-22T12_11_58_851Z-debug.log
synthtool > Wrote metadata to synth.metadata.

[codecov]

Codecov Report

Merging #294 into master will increase coverage by 0.53%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master     #294      +/-   ##
==========================================
+ Coverage    46.6%   47.13%   +0.53%     
==========================================
  Files          15       15              
  Lines        4221     4173      -48     
==========================================
  Hits         1967     1967              
+ Misses       2254     2206      -48

Impacted Files	Coverage Δ
src/v1/doc/google/rpc/doc_status.js	0% <0%> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 5defe2b...297d849. Read the comment docs.